Cystic ovarian disease in dairy cattle: Diagnostic accuracy when using B-mode and color Doppler ultrasound

The most frequently reported definition of cystic ovarian disease in cattle is an abnormally persistent follicle (>7 to 10 d) with a diameter >25 mm. Discrimination between luteal and follicular ovarian cystic structures has traditionally been conducted by measuring the rim width of luteal tissue. The most common practice used in the field for diagnosis of cystic ovarian disease is examination by rectal palpation with or without the use of a B-mode ultrasound. Color Doppler ultrasound technology allows assessment of blood flow area measurements in the ovary, which has been proposed as a potential indirect measure for plasma progesterone (P4) concentrations. The objective of this study was to compare the diagnostic accuracy of differentiating luteal structures from follicular ovarian cysts using measures collected with B-mode and color Doppler transrectal ultrasonography. The definition of an ovarian cyst was a follicle greater than 20 mm in diameter in the absence of a corpus luteum that persisted for at least 10 d. A 3-mm luteal rim width was used to differentiate follicular and luteal cysts. A total of 36 cows were enrolled in the study during routine herd reproductive examination visits, with 26 and 10 having follicular and luteal cysts, respectively. Cows enrolled in the study were examined using a Mini-ExaPad mini ultrasound with color Doppler capabilities (IMV Imaging Ltd.). Blood samples were collected from each cow to measure P4 serum concentrations. History and signalment of each cow, including days in milk, lactation, times bred, days since last heat, milk composition, and somatic cell counts, were retrieved from an online database (DairyComp 305, Valley Agricultural Software). The accuracy of diagnosing follicular from luteal cysts based on luteal rim thickness was analyzed by receiver operating characteristic (ROC) curve using P4 as the gold standard, where P4 concentrations exceeding 1 ng/mL was defined as luteal, and all other structures with less P4 were considered follicular. Luteal rim and blood flow area were selected for further analysis because they presented the best ROC curves for differentiating cystic ovarian structures, with areas under the curve of 0.80 and 0.76, respectively. Luteal rim width of 3 mm was used as the cutoff standard in the study, resulting in sensitivity and specificity of 50% and 86%, respectively. Blood flow area of 0.19 cm² was used as the cutoff standard in the study, resulting in sensitivity and specificity of 79% and 86%, respectively. When combining the use of luteal rim width and blood flow area to differentiate cystic ovarian structures, a parallel approach resulted in sensitivity and specificity of 73% and 93%, respectively, whereas an in-series approach resulted in sensitivity and specificity of 35% and 100%, respectively. In conclusion, the use of color Doppler ultrasonography when discriminating between luteal and follicular ovarian cysts in dairy cattle resulted in higher diagnostic accuracy compared with using B-mode ultrasonography alone.

Neuropathological and biochemical investigation of Hereditary Ferritinopathy cases with ferritin light chain mutation: Prominent protein aggregation in the absence of major mitochondrial or oxidative stress

AIMS

Neuroferritinopathy (NF) or hereditary ferritinopathy (HF) is an autosomal dominant movement disorder due to mutation in the light chain of the iron storage protein ferritin (FTL). HF is the only late-onset neurodegeneration with brain iron accumulation disorder and study of HF offers a unique opportunity to understand the role of iron in more common neurodegenerative syndromes.

METHODS

We carried out pathological and biochemical studies of six individuals with the same pathogenic FTL mutation.

RESULTS

CNS pathological changes were most prominent in the basal ganglia and cerebellar dentate, echoing the normal pattern of brain iron accumulation. Accumulation of ferritin and iron was conspicuous in cells with a phenotype suggesting oligodendrocytes, with accompanying neuronal pathology and neuronal loss. Neurons still survived, however, despite extensive adjacent glial iron deposition, suggesting neuronal loss is a downstream event. Typical age-related neurodegenerative pathology was not normally present. Uniquely, the extensive aggregates of ubiquitinated ferritin identified indicate that abnormal FTL can aggregate, reflecting the intrinsic ability of FTL to self-assemble. Ferritin aggregates were seen in neuronal and glial nuclei showing parallels with Huntington's disease. There was neither evidence of oxidative stress activation nor any significant mitochondrial pathology in the affected basal ganglia.

CONCLUSIONS

HF shows hallmarks of a protein aggregation disorder, in addition to iron accumulation. Degeneration in HF is not accompanied by age-related neurodegenerative pathology and the lack of evidence of oxidative stress and mitochondrial damage suggests that these are not key mediators of neurodegeneration in HF, casting light on other neurodegenerative diseases characterized by iron deposition.

Heterogeneity in α-synuclein subtypes and their expression in cortical brain tissue lysates from Lewy body diseases and Alzheimer's disease

AIMS

Lewy body diseases are neuropathologically characterized by the abnormal accumulation of α-synuclein (α-syn) protein within vulnerable neurons. Although studies have evaluated α-syn in post mortem brain tissue, previous findings have been limited by typically employing pan-α-syn antibodies that may not recognize disease-relevant forms of protein. We investigated the presence of α-syn species present in post mortem brain tissues from Lewy body disease and Alzheimer's disease.

METHODS

Soluble and insoluble/aggregated α-syn from frontal cortex of post mortem brain tissues form Parkinson's disease (PD), dementia with Lewy bodies (DLB), Alzheimer's disease (AD) and aged control cases were sequentially extracted using buffers with increasing detergent concentrations. Enzyme-linked immunosorbent assay (ELISA) was used to quantify the levels of total-, oligomeric- and phosphorylated-Ser129-α-syn (t-, o- and pS129-α-syn). ELISA data were validated by western blot and compared to histological data from the same region of the contralateral hemisphere.

RESULTS

There was no difference in t-α-syn levels between groups in the aqueous-soluble, detergent-soluble or urea-soluble tissue fractions. However, aqueous-soluble non-phosphorylated o-α-syn was increased not only in PD and DLB but also in AD without neocortical Lewy bodies. In PD and AD, pS129-α-syn was increased in the detergent-soluble tissue fragment and, in AD, this was positively correlated with the burden of tau pathology. Increased levels of urea-soluble pS129-α-syn were demonstrated only in DLB tissue lysates but this did not correlate with Lewy body pathological burden.

CONCLUSIONS

Taken together, these findings suggest that DLB have elevated levels of insoluble pS129-α-syn, but that increased levels of aqueous-soluble o-α-syn and detergent-soluble pS129-α-syn are also observed in PD and AD, suggesting different changes to α-syn across the spectrum of neurodegenerative proteopathies.

Exome sequencing in dementia with Lewy bodies

Dementia with Lewy bodies (DLB) is the second most common form of degenerative dementia. Siblings of affected individuals are at greater risk of developing DLB, but little is known about the underlying genetic basis of the disease. We set out to determine whether mutations in known highly penetrant neurodegenerative disease genes are found in patients with DLB. Whole-exome sequencing was performed on 91 neuropathologically confirmed cases of DLB, supplemented by independent APOE genotyping. Genetic variants were classified using established criteria, and additional neuropathological examination was performed for putative mutation carriers. Likely pathogenic variants previously described as causing monogenic forms of neurodegenerative disease were found in 4.4% of patients with DLB. The APOE ɛ4 allele increased the risk of disease (P=0.0001), conferred a shorter disease duration (P=0.043) and earlier age of death (P=0.0015). In conclusion, although known pathogenic mutations in neurodegenerative disease genes are uncommon in DLB, known genetic risk factors are present in >60% of cases. APOE ɛ4 not only modifies disease risk, but also modulates the rate of disease progression. The reduced penetrance of reported pathogenic alleles explains the lack of a family history in most patients, and the presence of variants previously described as causing frontotemporal dementia suggests a mechanistic overlap between DLB and other neurodegenerative diseases.

High-Resolution Faraday Rotation and Electron-Phonon Coupling in Surface States of the Bulk-Insulating Topological Insulator Cu_{0.02}Bi_{2}Se_{3}

We have utilized time-domain magnetoterahertz spectroscopy to investigate the low-frequency optical response of the topological insulator Cu_{0.02}Bi_{2}Se_{3} and Bi_{2}Se_{3} films. With both field and frequency dependence, such experiments give sufficient information to measure the mobility and carrier density of multiple conduction channels simultaneously. We observe sharp cyclotron resonances (CRs) in both materials. The small amount of Cu incorporated into the Cu_{0.02}Bi_{2}Se_{3} induces a true bulk insulator with only a single type of conduction with a total sheet carrier density of ~4.9×10^{12}/cm^{2} and mobility as high as 4000 cm^{2}/V·s. This is consistent with conduction from two virtually identical topological surface states (TSSs) on the top and bottom of the film with a chemical potential ~145 meV above the Dirac point and in the bulk gap. The CR broadens at high fields, an effect that we attribute to an electron-phonon interaction. This assignment is supported by an extended Drude model analysis of the zero-field Drude conductance. In contrast, in normal Bi_{2}Se_{3} films, two conduction channels were observed, and we developed a self-consistent analysis method to distinguish the dominant TSSs and coexisting trivial bulk or two-dimensional electron gas states. Our high-resolution Faraday rotation spectroscopy on Cu_{0.02}Bi_{2}Se_{3} paves the way for the observation of quantized Faraday rotation under experimentally achievable conditions to push the chemical potential in the lowest Landau level.

Singlet-Triplet Excitations and Long-Range Entanglement in the Spin-Orbital Liquid Candidate FeSc2S4

Theoretical models of the spin-orbital liquid (SOL) FeSc2S4 have predicted it to be in close proximity to a quantum critical point separating a spin-orbital liquid phase from a long-range ordered magnetic phase. Here, we examine the magnetic excitations of FeSc2S4 through time-domain terahertz spectroscopy under an applied magnetic field. At low temperatures an excitation emerges that we attribute to a singlet-triplet excitation from the SOL ground state. A threefold splitting of this excitation is observed as a function of applied magnetic field. As singlet-triplet excitations are typically not allowed in pure spin systems, our results demonstrate the entangled spin and orbital character of singlet ground and triplet excited states. Using experimentally obtained parameters we compare to existing theoretical models to determine FeSc2S4's proximity to the quantum critical point. In the context of these models, we estimate the characteristic length of the singlet correlations to be ξ/(a/2)≈8.2 (where a/2 is the nearest neighbor lattice constant), which establishes FeSc2S4 as a SOL with long-range entanglement.

Diquat causes caspase-independent cell death in SH-SY5Y cells by production of ROS independently of mitochondria

Evidence indicates that Parkinson's disease (PD), in addition to having a genetic aetiology, has an environmental component that contributes to disease onset and progression. The exact nature of any environmental agent contributing to PD is unknown in most cases. Given its similarity to paraquat, an agrochemical removed from registration in the EU for its suspected potential to cause PD, we have investigated the in vitro capacity of the related herbicide Diquat to cause PD-like cell death. Diquat showed greater toxicity towards SH-SY5Y neuroblastoma cells and human midbrain neural cells than paraquat and also MPTP, which was independent of dopamine transporter-mediated uptake. Diquat caused cell death independently of caspase activation, potentially via RIP1 kinase, with only a minor contribution from apoptosis, which was accompanied by enhanced reactive oxygen species production in the absence of major inhibition of complex I of the mitochondrial respiratory chain. No changes in α-synuclein expression were observed following 24-h or 4-week exposure. Diquat may, therefore, kill neural tissue by programmed necrosis rather than apoptosis, reflecting the pathological changes seen following high-level exposure, although its ability to promote PD is unclear.

Hierarchy of bound states in the one-dimensional ferromagnetic Ising chain CoNb2O6 investigated by high-resolution time-domain terahertz spectroscopy

Kink bound states in the one-dimensional ferromagnetic Ising chain compound CoNb2O6 have been studied using high-resolution time-domain terahertz spectroscopy in zero applied magnetic field. When magnetic order develops at low temperature, nine bound states of kinks become visible. Their energies can be modeled exceedingly well by the Airy function solutions to a 1D Schrödinger equation with a linear confining potential. This sequence of bound states terminates at a threshold energy near 2 times the energy of the lowest bound state. Above this energy scale we observe a broad feature consistent with the onset of the two particle continuum. At energies just below this threshold we observe a prominent excitation that we interpret as a novel bound state of bound states--two pairs of kinks on neighboring chains.

Polarization modulation time-domain terahertz polarimetry

We present high precision measurements of polarization rotations in the frequency range from 0.1 to 2.5 THz using a polarization modulation technique. A motorized stage rotates a polarizer at ~ 80 Hz, and the resulting modulation of the polarization is measured by a lock-in technique. We achieve an accuracy of 0.050° (900 μrad) and a precision of 0.02° (350 μrad) for small rotation angles. A detailed mathematical description of the technique is presented, showing its ability to fully characterize elliptical polarizations from 0.1 to 2.5 THz.

Mitochondrial dysfunction in Parkinson's disease

Parkinson's disease (PD) is a progressive, neurodegenerative condition that has increasingly been linked with mitochondrial dysfunction and inhibition of the electron transport chain. This inhibition leads to the generation of reactive oxygen species and depletion of cellular energy levels, which can consequently cause cellular damage and death mediated by oxidative stress and excitotoxicity. A number of genes that have been shown to have links with inherited forms of PD encode mitochondrial proteins or proteins implicated in mitochondrial dysfunction, supporting the central involvement of mitochondria in PD. This involvement is corroborated by reports that environmental toxins that inhibit the mitochondrial respiratory chain have been shown to be associated with PD. This paper aims to illustrate the considerable body of evidence linking mitochondrial dysfunction with neuronal cell death in the substantia nigra pars compacta (SNpc) of PD patients and to highlight the important need for further research in this area.

Aluminium accumulation, beta-amyloid deposition and neurofibrillary changes in the central nervous system

Deposition of beta-amyloid and the formation of neurofibrillary tangles (NFTs) are central to the aetiopathogenesis of Alzheimer's disease (AD). The possible effects of aluminium on these processes have been investigated in patients with renal failure who are exposed chronically to high blood levels of aluminium. Focal accumulation of aluminium was observed in neurons with high densities of transferrin receptors, indicating transferrin-mediated uptake, in regions such as cortex and hippocampus which are selectively vulnerable in AD. Increased staining for the beta-amyloid precursor protein (APP) in cortical pyramidal neurons was evident in the majority of renal patients and immature senile plaques were present in 30% of cases, suggesting that aluminium may induce or accelerate beta-amyloid deposition. The absence of neurofibrillary changes in this group of renal patients indicates that aluminium does not directly cause the formation of NFTs. The brain aluminium content was not raised in neuropathologically assessed cases of AD and we have been unable to confirm claims of defective transferrin binding in this disorder. If aluminium contributes to the development of sporadic AD, it must do so indirectly, perhaps via effects on the synthesis or metabolism of APP, or by contributing generally to the age-related attrition of neurons and thus reducing the threshold for deficits produced by more specific disease-related processes.

Urinary tract infection in infants and young children presenting with fever without a focus in Port Moresby

A prospective study was undertaken to document the importance of urinary tract infection (UTI) as a cause of fever without a focus (FWF) in children less than 3 years of age presenting to the Children's Outpatients Department (COPD) of Port Moresby General Hospital (PMGH). 98 children, 55 males and 43 females, with a median age of 17 months and an interquartile range of 5-31.25 months, were recruited. In addition to a history and physical examination each child had a full blood count, a malaria parasite smear, and a urine sample (obtained by clean catch or midstream methods) for dipstick testing, microscopy and culture. Blood culture was performed where practicable. Lumbar puncture and cerebrospinal fluid (CSF) examination were done only if clinically indicated. UTI was diagnosed on urine culture in 9 of the 98 children. Both urinary nitrite and leukocyte esterase tests were sensitive (89%) and specific (96%). Other causes of FWF were classified as non-specific viral infection (31 children), lower respiratory tract infection (11), malaria (7), meningitis (4), bacteraemia (1 neonate) and other or unknown causes. The finding of UTI in 9% of the children is consistent with data from other tropical countries. Checking for urinary tract infection, which can be done using noninvasive methods of urine collection, is an important part of the investigation of infants and children with FWF.

Individual dopaminergic neurons show raised iron levels in Parkinson disease

OBJECTIVE

Evidence suggests that abnormal iron metabolism is associated with Parkinson disease (PD), with raised iron levels found in pathologically affected areas in PD. It is unknown if this elevated iron is actually associated with neurons or reactive glia, and we therefore addressed this issue by determining if raised iron was present in single dopaminergic neurons.

METHODS

We used unfixed frozen sections from postmortem tissue of PD patients and elderly normal individuals to avoid metal contamination and translocation. Levels of iron and other elements were measured using sensitive and specific wavelength dispersive electron probe x-ray microanalysis coupled with cathodoluminescence spectroscopy in individual substantia nigra dopaminergic neurons.

RESULTS

We identified raised intraneuronal iron in single defined substantia nigra neurons in PD (mean neuronal iron 2,838 vs 1,611, p < 0.0001) but not in other movement disorders such as Huntington disease. These findings were unrelated to the density of remaining neurons.

CONCLUSIONS

Primary changes in neuronal iron could lead to neurodegeneration in Parkinson disease.

Growth, structural, and optical properties of self-assembled (In,Ga)as quantum posts on GaAs

Self-assembled quantum dots embedded in semiconductor heterostructures have proved to be a rich system for exploring the physics of three dimensionally confined charges and excitons. We present here a novel structure, which allows adjusting the level of confinement between 3D and 2D for electrons and holes, respectively. The quantum post consists of a quantum dot connected to a short quantum wire. The molecular beam epitaxy deposition of these self-assembled structures is discussed, and their structural and chemical compositions are presented. Their optical properties measured by photoluminescence are compared to an eight-band strain-dependent k.p model incorporating detailed structure and alloy composition. The calculations show electron delocalization in the quantum wire part of the quantum post and hole localization in the strain-induced regions at the ends of the quantum post. The quantum post offers the possibility of controlling the dipole moment in the structure and opens up new means for tuning the intra-subband transitions by controlling its dimensions.

Hereditary multi-infarct dementia of the Swedish type is a novel disorder different from NOTCH3 causing CADASIL

Several hereditary small vessel diseases (SVDs) of the brain have been reported in recent years. In 1977, Sourander and Wålinder described hereditary multi-infarct dementia (MID) in a Swedish family. In the same year, Stevens and colleagues reported chronic familial vascular encephalopathy in an English family bearing a similar phenotype. These disorders have invariably been suggested to be cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL) but their genetic identities remain unknown. We used molecular, radiological and neuropathological methods to characterize these disorders. Direct DNA sequencing unexpectedly confirmed that affected members of the English family carried the R141C mutation in the NOTCH3 gene diagnostic of CADASIL. However, we did not detect any pathogenic mutations in the entire 8091 bp reading frame of NOTCH3 or find clear evidence for NOTCH3 gene linkage in the Swedish DNA. This was consistent with the lack of hyperintense signals in the anterior temporal pole and external capsule in Swedish subjects upon magnetic resonance imaging. We further found no evidence for granular osmiophilic material in skin biopsy or post-mortem brain samples of affected members in the Swedish family. In addition, there was distinct lack of NOTCH3 N-terminal fragments in the cerebral microvasculature of the Swedish hereditary MID subjects compared to the intense accumulation in the English family afflicted with CADASIL. Several differences in arteriosclerotic changes in both the grey and white matter were also noted between the disorders. The sclerotic index values, density of collagen IV immunoreactivity in the microvasculature and number of perivascular macrophages were greater in the English CADASIL samples compared to those from the Swedish brains. Multiple approaches suggest that the Swedish family with hereditary MID suspected to be CADASIL has a different novel disorder with dissimilar pathological features and belongs to the growing number of genetically uncharacterized familial SVDs.

Apolipoprotein epsilon3 allele is associated with persistent hepatitis C virus infection

BACKGROUND

Host genetic factors may significantly influence the ability to clear hepatitis C virus (HCV) following infection. HCV is associated with very low density lipoproteins (VLDL) and low density lipoproteins (LDL) in the host's circulation. Apolipoprotein E (APOE) is found in VLDL and binds to potential receptors involved in HCV entry into cells, the LDL receptor, and the scavenger receptor protein SR-B1. The APOE gene is polymorphic with three alleles coding for three isoforms: Apo-epsilon2, Apo-epsilon3, and Apo-epsilon4. The aim of this study was to assess if these functional polymorphisms determine disease outcome in HCV infected individuals.

METHODS

The APOE genotype was determined in 420 Northern European patients with evidence of exposure to HCV. Genotype and allele distribution were compared with those of 288 healthy controls and progression of liver disease and viral clearance were analysed according to APOE allele status.

RESULTS

The APOE*E2 and APOE*E4 alleles were both associated with a reduced likelihood of chronic infection (odds ratio (OR) 0.39 (95% confidence interval (CI) 0.211-0.728), p = 0.003; and OR 0.6 (95% CI 0.38-0.96), p = 0.032) and there was a notable absence of the E2E2 genotype in the HCV antibody positive group compared with the control population (p = 0.0067). Overall the genotypes carrying the E2 allele (E2,E3 and E2,E4) were associated with the equivalent of a 3-5-fold reduction in the risk of chronic HCV infection (genotype relative risk 0.36 and 0.20, respectively).

CONCLUSION

This study indicates that functional APOE gene polymorphisms may be a determinant of outcome in HCV infection. We hypothesise that the E2 allele may protect against viral persistence via defective binding of HCV lipoviral particles to the cellular receptors involved in entry of these infectious particles.

Quantification of Alzheimer pathology in ageing and dementia: age-related accumulation of amyloid-beta(42) peptide in vascular dementia

Clinicopathological observations suggest there is considerable overlap between vascular dementia (VaD) and Alzheimer's disease (AD). We used immunochemical methods to compare quantities of amyloid-beta (Abeta) peptides in post mortem brain samples from VaD, AD subjects and nondemented ageing controls. Total Abeta peptides extracted from temporal and frontal cortices were quantified using a previously characterized sensitive homogenous time-resolved fluorescence (HTRF) assay. The HTRF assays and immunocapture mass spectrometric analyses revealed that the Abeta(42) species were by far the predominant form of extractable peptide compared with Abeta(40) peptide in VaD brains. The strong signal intensity for the peak representing Abeta(4-42) peptide confirmed that these N-terminally truncated species are relatively abundant. Absolute quantification by HTRF assay showed that the mean amount of total Abeta(42) recovered from VaD samples was approximately 50% of that in AD, and twice that in the age-matched controls. Linear correlation analysis further revealed an increased accumulation with age of both Abeta peptides in brains of VaD subjects and controls. Interestingly, VaD patients surviving beyond 80 years of age exhibited comparable Abeta(42) concentrations with those in AD in the temporal cortex. Our findings suggest that brain Abeta accumulates increasingly with age in VaD subjects more so than in elderly without cerebrovascular disease and support the notion that they acquire Alzheimer-like pathology in older age.

APOE epsilon4 and cognitive decline in older stroke patients with early cognitive impairment

BACKGROUND

Dementia is common post stroke, but the potential role of early cognitive impairment and APOE epsilon4 as risk factors is unclear.

METHOD

Stroke survivors older than 75 years without dementia at 3 months post stroke received a detailed neuropsychological evaluation at 3 and 15 months post stroke, which included the Cambridge Assessment of Mental Disorders in the Elderly (CAMCOG). Early cognitive impairment was diagnosed using the criteria for cognitive impairment/no dementia (vascular CIND). APOE genotype was determined using a standardized method.

RESULTS

One hundred thirty-seven older stroke patients without dementia (mean age 80.6 +/- 4.3, mean CAMCOG score 83.5 +/- 10.4, 68 women) participated in the study, of whom 40 met the criteria for CIND. Stroke patients with one or more APOE epsilon4 alleles were significantly more likely to have CIND (14/40 vs 17/97, odds ratio = 2.5, 95% CI 1.1 to 5.8). Over the 1 year of follow-up, CIND patients with one or more APOE epsilon4 alleles had a mean decline on the total CAMCOG of 2.7 points compared with an improvement of >4 points among patients without APOE epsilon4 (T = 2.9 p = 0.006). CIND patients with an APOE epsilon4 allele also experienced greater decline in memory (T = 2.5, p = 0.015).

CONCLUSION

In older stroke patients with early cognitive impairment, the presence of an APOE epsilon4 allele is associated with greater progression of cognitive decline. This has implications for interventions aimed at the secondary prevention of dementia in stroke patients.

Impact of hypertension and apolipoprotein E4 on poststroke cognition in subjects >75 years of age

BACKGROUND AND PURPOSE

The apolipoprotein E4 allele (APOE4) associates with increased dementia risk, and hypertension may associate with mild cognitive deficits. We examined whether nondemented stroke patients with (1) a prestroke history of hypertension and (2) APOE4 were more cognitively impaired at 3 months after stroke.

METHODS

A total of 257 participants were genotyped and outcomes from neuropsychological evaluations analyzed using regression.

RESULTS

Total Cambridge Assessment for Mental Disorders in the Elderly (CAMCOG) and speed of working memory significantly associated with hypertension. No outcomes significantly associated with APOE4.

CONCLUSIONS

Subjects with prestroke hypertension had more impaired global cognition and slower access to information held in working memory.

The H1c haplotype at the MAPT locus is associated with Alzheimer's disease

Although it is clear that microtubule associated protein tau (MAPT) is involved in Alzheimer's disease (AD) pathology, it has not been clear whether it is involved genetically. We have recently examined the MAPT locus in progressive supranuclear palsy and found that a haplotype (H1c) on the background of the well-described H1 clade is associated with PSP. Here we report that the same haplotype is associated with the risk of AD in two autopsy confirmed series of cases with ages at death >65 years.

Rate of progression of cognitive decline in Alzheimer's disease: effect of butyrylcholinesterase K gene variation

OBJECTIVE

To determine whether individuals with Alzheimer's disease (AD) and the K variant allele of butyrylcholinesterase have a slower rate of cognitive decline than those without the K variant allele of butyrylcholinesterase.

METHOD

The cognitive status of 339 community based subjects with AD was assessed with the Mini Mental State Examination at baseline and yearly over a three year follow up period. The rates of cognitive decline of subjects with and without the K variant allele were compared.

RESULT

Presence of the K allele was associated with a slower average rate of cognitive decline in subjects with severe AD.

CONCLUSIONS

This finding is consistent with the suggestion that the K variant of butyrylcholinesterase has an important role in disease progression in AD, and this may have implications for treatment.

Linkage disequilibrium fine mapping and haplotype association analysis of the tau gene in progressive supranuclear palsy and corticobasal degeneration

BACKGROUND

The haplotype H1 of the tau gene, MAPT, is highly associated with progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD).

OBJECTIVE

To investigate the pathogenic basis of this association.

METHODS

Detailed linkage disequilibrium and common haplotype structure of MAPT were examined in 27 CEPH trios using validated HapMap genotype data for 24 single nucleotide polymorphisms (SNPs) spanning MAPT.

RESULTS

Multiple variants of the H1 haplotype were resolved, reflecting a far greater diversity of MAPT than can be explained by the H1 and H2 clades alone. Based on this, six haplotype tagging SNPs (htSNPs) that capture 95% of the common haplotype diversity were used to genotype well characterised PSP and CBD case-control cohorts. In addition to strong association with PSP and CBD of individual SNPs, two common haplotypes derived from these htSNPs were identified that are highly associated with PSP: the sole H2 derived haplotype was underrepresented and one of the common H1 derived haplotypes was highly associated, with a similar trend observed in CBD. There were powerful and highly significant associations with PSP and CBD of haplotypes formed by three H1 specific SNPs. This made it possible to define a candidate region of at least approximately 56 kb, spanning sequences from upstream of MAPT exon 1 to intron 9. On the H1 haplotype background, these could harbour the pathogenic variants.

CONCLUSIONS

The findings support the pathological evidence that underlying variations in MAPT could contribute to disease pathogenesis by subtle effects on gene expression and/or splicing. They also form the basis for the investigation of the possible genetic role of MAPT in Parkinson's disease and other tauopathies, including Alzheimer's disease.

SNCA multiplication is not a common cause of Parkinson disease or dementia with Lewy bodies

The authors recently have shown that triplication of the alpha-synuclein gene (SNCA) can cause Parkinson disease (PD) and diffuse Lewy body disease within the same kindred. The authors assessed 101 familial PD probands, 325 sporadic PD cases, 65 patients with dementia with Lewy bodies, and 366 neurologically normal control subjects for SNCA multiplication. The authors did not identify any subjects with multiplication of SNCA and conclude this mutation is a rare cause of disease.

Influence of the amyloid precursor protein locus on dementia in Down syndrome

BACKGROUND

The amyloid precursor protein (APP) locus on chromosome 21 influences the development of Alzheimer disease.

METHOD

The authors investigated the relationship between a tetranucleotide repeat on intron 7 of the APP gene and the age at onset of dementia in Down syndrome (DS).

RESULTS

There was a 13-year difference in the age at onset of dementia in DS associated with the number of tetranucleotide repeat alleles in APP.

CONCLUSION

APP is an important locus predicting the age at onset of dementia in people with Down syndrome.

High throughput approaches in neuroscience

Traditional approaches to understanding biological problems are now being advanced with the use of high throughput technologies, which analyse multiple samples simultaneously, or thousands of analytes in a single sample. The application of these technologies in neurochemistry and neuroscience is beginning to be explored and is assisting in the development of new models of drug action, neuroanatomical investigations, and in identifying molecular pathways involved in neurological and psychiatric disease. Tools such as microarray-based gene expression profiling and 2D and multidimensional proteomic methods are uncovering functional components to a wide variety of neuroscience paradigms and the application of these technologies is set to become standard in analysis.

Functional genomics and proteomics: application in neurosciences

The sequencing of the complete genome for many organisms, including man, has opened the door to the systematic understanding of how complex structures such as the brain integrate and function, not only in health but also in disease. This blueprint, however, means that the piecemeal analysis regimes of the past are being rapidly superseded by new methods that analyse not just tens of genes or proteins at any one time, but thousands, if not the entire repertoire of a cell population or tissue under investigation. Using the most appropriate method of analysis to maximise the available data therefore becomes vital if a complete picture is to be obtained of how a system or individual cell is affected by a treatment or disease. This review examines what methods are currently available for the large scale analysis of gene and protein expression, and what are their limitations.

CADASIL and genetics of cerebral ischaemia

Recent advances suggest the existence of several autosomal dominantly inherited forms of cerebrovascular disorders. Mutations in diverse genes may induce direct pathological changes in intracranial vessels to cause cerebral ischaemic or haemorrhagic strokes leading to cognitive impairment and dementia. Similar pathology may also be caused by systemic vascular disease resulting from mutations and polymorphisms in genes that regulate cardiovascular physiology, blood coagulation and metabolic functions. The most common form of familial stroke appears to be CADASIL or cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy. CADASIL is an arterial disease that has been linked to nucleotide substitutions and deletions in the Notch 3 gene. The pathogenesis of the disorder or how the mutations lead to cerebral infarcts and dementia is not known. However, elucidation of the microvascular pathology associated with such genetic disorders not associated with physiological risk factors for cardiovascular disease or stroke can bear much light on primary vascular mechanisms that lead to ischaemic blood flow and neuronal vulnerability.

A full-length and potentially active LINE element is integrated polymorphically within the IGL locus in a genomically unstable region of chromosome 22

Leukemic cells of a patient diagnosed with chronic myeloid leukemia (CML) showed a complex BCR-ABL1 rearrangement hidden within a normal appearing karyotype. Previous molecular studies had established that the 3' BCR had recombined at a novel site within the variable region of the immunoglobulin lambda locus ( IGL). A segment of DNA mapping very close to the site of the IGL/3' BCR recombination recognized a previously undescribed insertion polymorphism. A combination of molecular hybridization studies and long-range polymerase chain reaction was used to isolate a 6-kb full-length long interspersed nuclear element (LINE or L1), here designated L1(IGL), which occupies 19% of alleles in the general population. Although unclonable, DNA sequence analysis by a primer walking approach established that L1(IGL) has features characteristic of an actively retrotransposing element. The L1(IGL) element has a 5' untranslated region, two open reading frames (ORF-1 and ORF-2), a 3' untranslated region and terminates in a poly-A tail. We compared the DNA sequence and the predicted amino acid sequence of L1(IGL) with a consensus sequence compiled from seven reported active L1 elements. This analysis indicated that L1(IGL) has high potential for involvement in as yet undetermined somatically and constitutionally acquired disease, not only through recombination mechanisms, but also through retrotransposition events. This full-length L1 element maps close within the IGLlocus to L1.2, one of only nine active L1 elements that have been reported so far. L1(IGL) and L1.2 map within a wider and well-recognized region of genomic instability on chromosome 22.

Nonrandom distribution of interspersed repeat elements in the BCR and ABL1 genes and its relation to breakpoint cluster regions

The Philadelphia translocation, t(9;22)(q34;q11), is the microscopically visible product of recombination between two genes, ABL1 on chromosome 9 and BCR on chromosome 22, and gives rise to a functional hybrid BCR-ABL1 gene with demonstrated leukemogenic properties. Breakpoints in BCR occur mostly within one of two regions: a 5 kb major breakpoint cluster region (M-Bcr) and a larger 35 kb minor breakpoint cluster region (m-Bcr) towards the 3' end of the first BCR intron. By contrast, breakpoints in ABL1 are reported to occur more widely across a >200 kb region which spans the large first and second introns. The mechanisms that determine preferential breakage sites in BCR, and which cause recombination between BCR and ABL1, are presently unknown. In some cases, Alu repeats have been identified at or near sequenced breakpoint sites in both genes, providing indications, albeit controversial, that they may be relevant. For the present study, we carried out a detailed analysis of genomic BCR and ABL1 sequences to identify, classify, and locate interspersed repeat sequences and to relate their distribution to precisely mapped BCR-ABL1 recombination sites. Our findings confirm that Alu are the most abundant class of repeat in both genes, but that they occupy fewer sites than previously estimated and that they are distributed nonrandomly. r-Scan statistics were applied to provide a measure of repeat distribution and to evaluate extremes in repeat spacing. A significant lack of Alu elements was observed across the major and minor breakpoint cluster regions of BCR and across a 25-kb region showing a high frequency of breakage in ABL1. These findings counter the suggestion that occurrence of Alu at BCR-ABL1 recombination sites is likely by chance because of the high density of Alu in these two genes. Instead, as yet unidentified DNA conformation or nucleotide characteristics peculiar to the preferentially recombining regions, including those Alu elements present within them, more likely influence their fragility.

Mutation in the gene encoding ferritin light polypeptide causes dominant adult-onset basal ganglia disease

We describe here a previously unknown, dominantly inherited, late-onset basal ganglia disease, variably presenting with extrapyramidal features similar to those of Huntington's disease (HD) or parkinsonism. We mapped the disorder, by linkage analysis, to 19q13.3, which contains the gene for ferritin light polypeptide (FTL). We found an adenine insertion at position 460-461 that is predicted to alter carboxy-terminal residues of the gene product. Brain histochemistry disclosed abnormal aggregates of ferritin and iron. Low serum ferritin levels also characterized patients. Ferritin, the main iron storage protein, is composed of 24 subunits of two types (heavy, H and light, L) which form a soluble, hollow sphere. Brain iron deposition increases normally with age, especially in the basal ganglia, and is a suspected causative factor in several neurodegenerative diseases in which it correlates with visible pathology, possibly by its involvement in toxic free-radical reactions. We found the same mutation in five apparently unrelated subjects with similar extrapyramidal symptoms. An abnormality in ferritin strongly indicates a primary function for iron in the pathogenesis of this new disease, for which we propose the name 'neuroferritinopathy'.

Multiple substrates of late-onset dementia: implications for brain protection

Age is the single most important risk factor for progressive dementia in populations worldwide. In developed countries the prevalence of dementia is estimated to be 3-5% at age 65 years and expected to double every decade thereafter. Although there is ageing-related attrition of neural tissue accompanied by profound changes in brain glia, marked neuronal loss and severe cognitive impairment are associated with pathological changes. Accelerated somatic ageing of the vasculature comprising endothelial and smooth muscle cells and slowed glial replacement are also likely to pre-dispose to degenerative processes. Approximately 90% of patients with late-onset dementia have neuropathological features of Alzheimer's disease (AD), dementia with Lewy bodies (DLB), or vascular dementia (VaD), alone or in combination. Both AD and DLB reveal extensive amyloid beta deposition within senile plaques. Neurofibrillary tangles evident as tau pathology are much reduced in DLB where symptoms may be more related to cholinergic transmitter abnormalities than structural pathology. Depletion of brain acetylcholine is also encountered in VaD, which like AD and DLB may respond to cholinergic therapy. Cerebrovascular pathology, ischaemic brain damage and neurovascular instability resulting in cerebral hypoperfusion appears fundamental in the pathogenesis of late-onset dementia. The apolipoprotein E epsilon 4 allele, a major genetic susceptibility factor for AD also associated with cardiovascular pathology, may contribute to neurodegenerative changes through vascular mechanisms. The interrelationships of these multiple substrates of late-onset dementia have major implications for neuroprotective and disease slowing therapies. Measures that improve cardiovascular function and increase brain perfusion would be useful to attenuate cognitive decline.

The progression of cognitive impairment in dementia with Lewy bodies, vascular dementia and Alzheimer's disease

BACKGROUND

Little is known about the rate of progression or associations of cognitive impairment in dementia with Lewy bodies (DLB), or the associations of accelerated decline.

METHOD

Dementia patients from a case register were evaluated at baseline and 1 year follow-up using the Cambridge Assessment for Mental Disorders in the Elderly, section B (CAMCOG) and the Mini-Mental State Examination (MMSE) to determine the rate of cognitive decline. Operationalized clinical diagnoses were applied (NINCDS ADRDA for Alzheimer's disease (AD), NINCDS AIRENS for vascular dementia (VaD) and consensus criteria for DLB).

RESULTS

One hundred and ninety-three patients completed annual MMSE schedules (AD, 101; DLB, 64; VaD, 38), of whom 154 completed the CAMCOG. The magnitude of cognitive decline (MMSE, 4-5 points; CAMCOG, 12-14 points) was similar in each of the dementias. The strongest predictor of accelerated cognitive decline in DLB was the apolipoprotein E4 allele (17.5 vs 8.3 points decline on the CAMCOG).

CONCLUSION

Over 1 year, DLB, VaD and AD patients had similar rates of cognitive decline overall. Apolipoprotein E4 may be an important predictor of more rapid decline in DLB.

Nitric oxide synthase gene polymorphisms in Alzheimer's disease and dementia with Lewy bodies

Evidence suggests that vascular and inflammatory components may be important in the aetiology of dementia and genetic risk factors affecting these processes may therefore influence disease development. Recently, polymorphisms in the endothelial constitutive nitric oxide synthase 3 (NOS3) and also the inducible nitric oxide synthase gene (NOS2A) have been suggested to lead to increased risk of Alzheimer's disease (AD) or dementia with Lewy bodies. We have studied the relationship of both these NOS gene polymorphisms to development of AD and dementia with Lewy bodies and find no evidence for association with either condition. We conclude that NOS gene polymorphisms do not alter disease risk in the majority of late-onset dementia cases.

Pathology of early-onset Alzheimer's disease cases bearing the Thr113-114ins presenilin-1 mutation

Most cases of familial presenile Alzheimer's disease are caused by mutations in the presenilin-1 (PSEN-1) gene, most of these mutations being missense mutations. A mutation in the splice donor site of intron 4 of PSEN-1 has been described recently which results in aberrant splicing of PSEN-1 mRNA, causing insertion of an additional amino acid, Thr113-114ins, into the protein. We studied the neuropathology of four cases bearing this mutation in an attempt to clarify the pathology of this hereditary form of Alzheimer's disease and to determine whether it differs from other familial forms of the disease. The disease presented as a progressive cognitive decline, myoclonus and seizures developing later in the disease, a feature common to PSEN-1-linked Alzheimer's disease. The course of the disease was relatively rapid, death occurring approximately 6 years after onset. Pathology in the intron 4 cases demonstrated a severe Alzheimer's disease pathology with abundant deposition of ss-amyloid (Ass) 1-42 senile plaques and the formation of neurofibrillary tangles. Amyloid angiopathy was present in these cases and was readily demonstrated by Ass 1-40 staining, particularly in the cerebellum. Cases with the intron 4 mutation appear clinically and pathologically similar to other cases of early-onset Alzheimer's disease bearing PSEN-1 mutations.

Brain matrix metalloproteinase 1 levels are elevated in Alzheimer's disease

Several lines of evidence indicate that there may be an inflammatory component to the pathology of Alzheimer's disease (AD), the major form of degenerative dementia in the elderly. Activity of inflammatory cells, and the elaboration of toxic molecules by such cells may be a significant factor in disease progression. In peripheral inflammatory states, the increased activity of matrix metalloproteinase (MMP) enzymes are a major cause of tissue breakdown and secondary damage in diseases such as rheumatoid arthritis. The activity of such enzymes in the normal or diseased central nervous system is, however, not well characterized. We have therefore determined the levels of MMP 1 (collagenase) in the normal human brain and in AD. MMP1 levels were relatively low though were significantly elevated by approximately 50% in AD in all cortical areas examined. Given the activity towards collagen of MMP1, it is possible that enhanced MMP1 activity in AD, may contribute to the blood-brain barrier dysfunction seen in AD.

The small GTPase RAC3 gene is located within chromosome band 17q25.3 outside and telomeric of a region commonly deleted in breast and ovarian tumours

The closely related small GTP-binding proteins Rac1, Rac2, and Rac3 are part of a larger Rho subfamily of Ras proteins. Because disruption of Ras signaling pathways is relevant to the pathogenesis of a wide variety of cancers, it is important to clearly define the structural and functional characteristics of the participating proteins and their encoding genes. Rho subfamily members are involved in a range of signal transduction pathways relevant to cell growth, differentiation, motility, and stress, and Rac proteins are now recognised as a necessary component of Ras-mediated cellular transformation. We previously mapped RAC3 to chromosome band 17q23--> q25, a region that contains a number of candidate tumour suppressor genes. Because of its oncogenic potential, we have now further refined the location of this gene. Here we confirm that RAC3 maps to chromosome band 17q25.3 and further show that it maps some distance telomeric of a well-characterised minimal breast and ovarian candidate tumour suppressor gene region, BROV. The genomic structure of RAC3, including exon and intron boundaries, is also presented.

Mitochondrial DNA haplogroups and susceptibility to AD and dementia with Lewy bodies

The authors analyzed the relationship between nuclear genetic risk factors (apolipoprotein E genotype) and mitochondrial DNA (mtDNA) sequence variants in pathologically proved cases of AD (n = 185), dementia with Lewy bodies (DLB; n = 84), and control subjects (n = 179). Specific European mtDNA haplogroups and the A4336G mutation were not associated with an increased risk of AD. mtDNA haplogroup H was overrepresented in the DLB patients when compared with control subjects. Additional studies are needed to clarify the significance of the association.

Brain oestradiol and testosterone levels in Alzheimer's disease

Epidemiological studies indicate that oestrogen improves memory and may delay the onset of Alzheimer's disease (AD) in postmenopausal women. Furthermore, evidence from experimental studies suggests beneficial effects of oestrogen on several pathogenic mechanisms implicated in AD. We have therefore measured the levels of oestradiol and testosterone in control and AD brains. The results show that in control brain, oestradiol levels are 3.5 fold higher in females than males, though testosterone levels are equivalent. In AD, oestradiol levels were not significantly increased compared to those in control brain, while testosterone levels were unaffected in AD. The results do not support the hypothesis that a lack of oestrogen is a contributory factor in AD.

The integrin alpha10 subunit: expression pattern, partial gene structure, and chromosomal localization

Herein we report the cloning of cDNAs and incompletely processed hnRNAs from endothelia and heart that encode the alpha10 subunit forming part of the novel collagen type II-binding integrin alpha10beta1 of chondrocytes. Analysis of hnRNA clones and reported expressed sequence tags revealed the positions of 17 putative intron-exon splice junctions shared with those of the p150,95 (ITGAX) gene. Human alpha10 transcripts of 5.4 and 1.8 kb were not restricted to chondrocytes but, instead, were widely expressed in a panel of 24 tissue types, where the highest expression was found in muscle and heart. The human alpha10 subunit gene (ITGA10) was localized to band q21 of chromosome 1.

Trisomy 10 in acute myeloid leukemia: three new cases

Trisomy 10 is a rare nonrandom cytogenetic abnormality found in association with acute myeloid leukemia (AML). The hematological and clinical features associated with this finding have not yet been clearly defined. A literature review revealed 13 cases of trisomy 10 in AML, some reported as a minority component of a more comprehensive AML study and therefore lacking a full description of both clinical and hematological features. We present a summary of these reports and add three new cases to the literature.

Cutting needle biopsy in the diagnosis of clinically suspected non-carcinomatous disease of the lung

Most patients referred for lung biopsy have a focal lesion that is likely to be a carcinoma, and fine needle aspiration is usually sufficient to confirm the diagnosis. When non-carcinomatous disease is suspected, tissue architecture is important and potential diagnostic techniques include percutaneous cutting needle biopsy (CNB). We retrospectively reviewed 37 CNBs performed for clinically suspected non-carcinomatous disease; recording the biopsy result, final diagnosis, radiological nature of the pulmonary abnormality, distance from the pleura of the lesion biopsied and biopsy complications. 9 patients had a single pulmonary nodule/mass; 13 had multiple nodules/masses; 8 had a lobar consolidation/mass; and 7 had multifocal consolidation. The lesion abutted the pleura in 31 cases, lying within 1 cm in the other 6 cases. The minor complication rate was 14%, with no major complications. Specific malignant diagnoses were made in 9 patients, and specific benign in 23, in all of whom clinicoradiological follow-up was concordant. CNB did not yield a specific diagnosis in five patients, including two lymphomas and one case of unsuspected tuberculosis in which the sample was not cultured. The overall accuracy of CNB was 32/37 (86%). CNB is a safe and accurate means of achieving a tissue diagnosis for patients with peripheral pulmonary parenchymal disease thought not to represent carcinoma.

Distribution of amyloid beta 42 in relation to the cerebral microvasculature in an elderly cohort with Alzheimer's disease

Amyloid beta (A beta) deposits and neurofibrillary pathology are characteristic features of Alzheimer's disease (AD). The association of A beta with cerebral vessels is an intriguing feature of AD. While some degree of cerebral A beta angiopathy involving the leptomeninges and intraparenchymal vessels occurs in almost all cases of AD, the proportion of microvessels within a neocortical region containing deposits of A beta peptide is not known. In this study, we examined a cohort of clinically and pathologically evaluated AD cases to assess the percentage of cerebral microvessels in the temporal cortex and parahippocampal gyrus associated with the predominant, A beta 42 form of the peptide. We also assessed whether the distribution and burden of amyloid was related to apolipoprotein E (APOE) genotype. Using double immunostaining methods, we surprisingly found that at least 40% of the microvessels in the two brain regions contained A beta 42 deposits. There was no correlation of such localization with APOE genotype, however, epsilon 4 homozygotes revealed a greater burden of A beta 40. These observations suggest that high proportions of cortical microvessels are associated with A beta 42, which may affect microvascular function.

Hereditary vascular dementia linked to notch 3 mutations. CADASIL in British families

The most common form of familial vascular dementia is considered to be CADASIL or cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, which is now also increasingly manifest in the United Kingdom. CADASIL has been previously dubbed as a familial form of Binswanger disease. However, unlike in Binswanger disease CADASIL does not involve hypertension or other risk factors associated with cardiovascular disease. CADASIL appears to be essentially a disorder of the arteries that is linked to single missense mutations in the NOTCH 3 gene locus on chromosome 19. The pathogenesis of the disorder or the genetic mechanism leading to brain infarcts and dementia is not known. The elucidation of the microvascular pathology evident in CADASIL may be an interesting way to delineate effects of defective genes on brain cells from systemic vascular influences.